This invention relates to an apparatus for successively winding continuous strips of material into rolls, the apparatus including at least one upstanding guide frame for slide bearings of winding shafts for the material to be wound. The guide frame has an outer frame member and an inner frame member which together with the outer frame defines a guide track along which the slide bearings are guided.
The strips of material to be wound include paper, non-woven fabric, textiles, foil, strips of synthetic material such as thermoplastics, metal foil strips such as aluminum or copper, strip-shaped compound material such as coated paper strips, multi-layered plastic strips with individual layers of different plastic material, etc.
The term "winding" of rolls throughout this application is intended to also include the rewinding of rolls as understood in this art.
The apparatus provides for the rewinding of large rolls of the material into rolls of smaller diameter and/or smaller width. The apparatus may also be employed as a work station in installations which includes sheet dies for the extrusion of plastified thermoplastic material into plastic strips.
A problem encountered in the winding of rolls of material concerns maintaining the operational interruptions during the winding of successive rolls as short and as infrequent as possible to assure continuous operation of the apparatus.
A known apparatus of continuous operation has reversing winders with winding shafts arranged in the form of a rotary cross. However, costly auxiliary devices are required to assure an interrupted continuous operation.
European Patent No. 0 145 029 discloses an apparatus of the type generally described above as having an upstanding guide frame. At the input feed station for the strips of material, the ends of the winding shaft, on which a sleeve core for the roll to be wound is supported, are coupled to slide bearings and then moved to a roll forming station at which the strips are wound into rolls of a predetermined diameter. At the material infeed location spaced from the guide frame is provided an upstanding column with a height adjustable slide bearing which, in its upper position, is coupled to the free end of the winding shaft and is then lowered to the roll forming station together with a slide bearing supported in the guide frame.
After the roll is wound, the slide bearing on the column is decoupled from the winding shaft while the slide bearing supported in the guide frame, to which the winding shaft and wound roll is supported, is transported to a roll removal station by supporting the free end of the winding shaft by a guide rail.
During this interval the slide bearing on the column is raised to its upper position, is coupled to the free end of an empty winding shaft which is then lowered to the roll forming station for winding the next roll, and the aforedescribed operation is continued.
Another embodiment disclosed in this patent provides for a continuous roll winding operation by the provision of another upstanding guide frame having two coupling devices in place of the guide column with its height adjustable slide bearing. One of the coupling devices is coupled to the winding shaft on which a roll is wound, while the other coupling is coupled to the winding shaft on the next slide bearing of the other guide frame, and the winding shaft is lowered with its slide bearing and such other coupling device to the roll forming station at which, simultaneously, depending on the diameter of the roll to be wound, the respective winding shaft with the slide bearing end of the first coupling device is moved to the roll removal station such that after winding the last layer of the roll the strip is transversely cut forming a leading edge of the strip which is fed without interruption of the operation onto the sleeve core of the next winding shaft.
Problems may, however, be encountered particularly when the phase times, i.e., the winding times for the individual rolls, become very short.
Moreover, other problems could occur with operation with such a guide frame in that the closed guide track delineated by inner and outer frame members of the guide frame, is in the form of a rectangle or rhombus of such arrangement that unstable conditions for the slide bearings may be presented at the corners of the guide track since a plane support at the corners of the inner frame member cannot be provided.
A solution to this problem, although cumbersome, is to provide catches which reach behind the slide bearings in such a manner to prevent the instabilities at the corner areas.